Clair vs Kyverno

Clair is free, self-hosted software that continuously scans container images for vulnerabilities in operating-system bases, installed packages, and programming-language components. Clients use its API to index images and match them against known vulnerabilities. Clair updates its vulnerability database as new issues appear and can reanalyze images without rereading their complete contents. It supports OCI Distribution and Docker v2 images, and lists RHEL, Alpine, Ubuntu, Debian, Oracle, Photon, and SUSE distributions, plus Java, Python, Golang, and Javascript. Deployment options include microservices, monolithic installations, CI pipelines, and disconnected environments. Clair can run as an indexer, matcher, notifier, or combo process. It uses PostgreSQL for persistence and is released as a Quay.io container, with the clairctl command-line tool among its artifacts. Clair runs on Linux, supports registry scanning, and is licensed under Apache 2.0. Runtime protection is not provided.

Kyverno is a free, open-source policy engine for defining and enforcing policy as code in Kubernetes. Its stable policy types can validate, mutate, generate or delete resources, and verify container image signatures and attestations. The Kyverno CLI can test policies against Kubernetes resource manifests in CI before they are applied to a live cluster. Documentation describes use with Helm, YAML manifests, GitHub Actions and GitOps tools such as ArgoCD. Kyverno is installed in a Kubernetes cluster; Helm is recommended for production, and YAML manifests are also available. A standard installation requires an admission controller, while background, reports and cleanup controllers are optional. Production installations should use high availability mode. The project supports CEL-based policy types and describes applying Kubernetes-style policies outside Kubernetes as part of its mission. Its webhooks default to fail-closed, so matching requests can fail if the API server cannot reach Kyverno. The project documents Cosign signatures for images and manifests, and lists CLI binaries for Linux, macOS and Windows.